Strange Electrical Problem

[bikerbob]

BSA A7 1956 swinging arm. Went out this morning to start the bike has not been run for a couple of weeks started no problem but was not showing a charge with the lights on or off then the lights went off pressed the horn button no sound but ammeter shows full charge not a discharge, stopped the engine pressed the horn nothing no sound or movement on the ammeter also no lights. Checked the battery fully charged but still no lights or horn. Decided to start the bike again now everything is working as it should be, and all OK charging with headlight on horn works as it should, stopped the engine and lights and horn work OK showing normal discharge on ammeter. Baffled as to what caused the initial problem, and unable to find anything wrong as everything is now working as it should any ideas out there thanks.

[Andreas Larsen]

Have you looked inside the headlight to see if all the connections are good? If one of the connections at the ammeter are loose or bad, could it cause the problem you describe?

[bikerbob]

Thanks for that will have a look tomorrow

[Angus]

I had a similar problem, happened three times and then stop working all together. It turned out to the the replacement ammeter. Bought another one (paid more  ) and has been fine since.

[WozzA]

My .02c worth is a loose connection or crook main fuse from the battery if you have one?   

[Triton Thrasher]

Is the horn fed through the fuse and ammeter?

If not, then everything being dead including the horn would make me suspect a bad connection at a battery terminal, or where the battery's earth lead is attached to the frame or engine.

[bikerbob]

Have found the cause of the problem it was the fuse holder not making a good enough contact with the fuse, the fuse was too loose in the holder put a piece of brass round bar in the holder this tightened everything up all OK now. Thanks for the responses.